Pollution characteristics, associated risks, and possible sources of heavy metals in road dust collected from different areas of a metropolis in Vietnam

Road dust samples were collected from different areas in Ho Chi Minh City (HCMC)-the largest city in Vietnam to explore pollution characteristics, ecological and human health risks, and sources of heavy metals (HMs). Results revealed the level of HMs found in the samples from residential and industrial zones of HCMC in the order of Mn > Zn > Cu > Cr > Pb > Ni > Co > As > Cd, Zn > Mn > Cu > Cr > Pb > Ni > Co > As > Cd. Due to the high enrichment of Cu, Zn in residential areas and Cu, Pb, Zn in industrial areas, the HM contamination in these areas remained moderate to severe. The findings also revealed a rising trend in the level of HMs in road dust from the east to the west of HCMC, and a heavy metal contamination hotspot in the west. In addition, industrial areas were more contaminated with HMs, posing greater associated risks than residential areas. Children living in urban areas of HCMC were found to be exposed to unacceptable health risks. Meanwhile, adults living in industrial areas face intolerable cancer risk. Among the nine HMs, Cd, Pb, and Cu posed the greatest ecological risk, while Cr and As were the main culprits behind health risks. HMs in road dust might derive from non-exhaust vehicular emissions, crustal materials, and industrial activities. The results suggested that industrial areas to the west of HCMC should focus more on reducing and controlling severe pollution of HMs.

Automated summary

Road dust samples from different areas in Ho Chi Minh City (HCMC) were analyzed to study pollution characteristics, ecological and human health risks, and sources of heavy metals (HMs). The study found that HMs like Mn, Zn, Cu, Cr, Pb, Ni, Co, As, and Cd were present in the samples, with higher concentrations in residential and industrial zones. The level of HMs increased from east to west in HCMC, with a hotspot of heavy metal contamination in the west. Industrial areas were more contaminated and posed greater risks than residential areas. Children living in urban areas faced unacceptable health risks, while adults in industrial areas faced intolerable cancer risk. Cd, Pb, and Cu posed the highest ecological risk, while Cr and As were the main culprits behind health risks. HMs in road dust could originate from vehicular emissions, crustal materials, and industrial activities. The study suggests the need for pollution control measures, particularly in the industrial areas in the west of HCMC.